There is proposed a navigation system preventing unauthorized use of map information by users (refer to Patent Document 1). Here, encrypted licensing codes are used for licensing the user. Namely, the licensing codes include a map designating code for designating a map storage medium, a device designating code for designating a navigation system using the map storage medium, and a user authorized region code for indicating a region of multiple map information items for a user to be allowed to access. The encrypted licensing codes are decrypted and verified, and then a user can start to use the licensed map information.
Patent Document 1: JP-2002-62142 A
In the above system, the device designating code is formed as a unique code by combining a product number, a serial number, and the like of the navigation system. This formed device designating code is previously stored in a storage device of the navigation system when shipment. This involves additional steps relating to the device designating code as developing steps, so that the costs of the system are expected to increase.
Further, this needs hardware devices or software programs dedicated for decrypting the licensing code, which also leads to increase in the costs of the system.